The prior art, as exemplified in U.S. Pat. Nos. 2,900,446, 3,522,664, 3,591,718, 3,699,439 and 3,798,370, contains a number of graphical entry devices employing rectangular resistive sheets or planes. Voltages are alternately applied across the opposite edges of the rectangular resistive plane and the analogue value of a voltage generated on a contact probe, a capacitance probe or a depressed portion of a conductor sheet overlying the resistance plane is sensed to determine the two-dimensional position of the probe or depressed portion. When the rectangular resistive planes are energized by means of electodes connected directly to the edges of the resistive plane, such as in the above-mentioned U.S. Pat. No. 2,900,446, the electrodes on the non-energized edges shunt such edges to produce nonlinearity of the voltage gradient within the adjacent portions of the resistance plane. In the U.S. Pat. Nos. 3,522,664 and 3,699,439, point electrodes spaced along each of the sides are isolated by pluralities of diodes connected to the energizing source; the use of pluralities of diodes to isolate the edge contact points substantially increases the cost of the graphical entry device. Another arrangement for increasing the linearity within a rectangular resistive plane as disclosed in the U.S. Pat. Nos. 3,591,718 and 3,798,370 includes low resistance connections to the edges of the rectangular area so that the non-energized edges are maintained linear by means of voltage gradients in the low resistance edges; this requires relatively large operating currents as well as producing heating and electromagnetic interference which are generally undesirable in devices for low-power electronic circuits.